The present invention generally relates to a capsule filling machine and more particularly, to an apparatus for filling viscous substances into hard gelatin capsules.
As is generally known, gelatin capsules, for example, for use in pharmaceutical industry are classified into hard capsules and soft capsules, and commonly, powdered or granular substances are filled into the hard capsules each composed of a cylindrical open-ended body and a cap similar in shape to the body and applied onto the body with the open end of said body inserted into said cap, while oily substances in liquid forms are filled into the soft capsules so as to be respectively utilized as useful medicines.
As compared with the solid medicines such as powdered or granular medicines, the liquid medicines generally have such advantages as easiness in uniform dispersion of the active component in a carrier employed and precise distribution of the mixture obtained. However, even if the liquid medicine is filled as it is into the hard capsules, it undesirably leaks from the coupling portion between the body of the capsule and the cap thereof, and therefore, such a hard capsule is not suitable for practical application in the above case. Although a band seal applied onto the periphery of the coupling portion of the body and cap may prevent leakage of the liquid medicine, an extra operation is required during the filling process, thus resulting in unfavorable rise in manufacturing cost.
For such reasons, the liquid medicine has been inevitably filled into soft capsules. However, since special apparatuses are required for the production of the soft capsule-contained medicines, the manufacture of such soft capsule-contained medicines is normally performed by the so-called outside contract manufacturers, instead of being effected by the pharmaceutical company, thus presenting a new problem in the aspect of processing.
Due to the recent remarkable progress in the studies for prescriptions of the contents to be filled into the capsules, there has been developed a new medicine composition which has fluidity and viscosity and yet, may be filled into ordinary hard gelatin capsules without leakage, as disclosed, for example, in Japanese Laid Open Patent Application, Tokkaisho 54-80407. Thus, it is anticipated that the hard capsule-contained medicine filled with viscous substances will soon be put into practical use, but no capsule packing machines employed therefor up to the present have been fully satisfactory for the purpose. Accordingly, development of a new capsule filling machine for viscous substances has been strongly desired in this line of trade, and the present invention is provided to meet such requirements.
For the viscous substances suitable for filling into hard capsules, it is required to have a proper fluidity in terms of the operational efficiency during the filling and to cake or gel after the filling so as to prevent its leakage from the capsule.
The composite substance having such physical properties is fully disclosed in the aforesaid Japanese Laid Open Patent Application, and in short, is water soluble and thermally fusable substance having a caking point ranging from 20.degree. to 60.degree. C. and/or thixotropic gel. When the above substance is filled into hard capsules, there is employed a method in which the substance is filled while being heated, and then cooled at room temperature after the filling so that it may cake, or a method in which it is filled while being agitated so as to increase its fluidity in terms of the thixotropy of and then external force is removed after the filling so that it may gel. The apparatus for embodying such a filling method as described above is required to be specially arranged, taking into consideration the characteristics of the viscous substance to be filled and also particular structure of the hard gelatin capsule as a filling container.
Accordingly, an essential object of the present invention is to provide an apparatus which is capable of filling viscous substances into hard gelatin capsules in an efficient manner.
Another important object of the present invention is to provide an apparatus of the above described type which is simple in construction and accurate in functioning at high reliability, and can be readily manufactured at low cost.
In accomplishing these and other objects, according to one preferred embodiment of the present invention, there is provided an apparatus for filling viscous substances into hard gelatin capsules which includes a hopper member capable of storing viscous substance to be filled at a predetermined temperature and under agitation, a pumping mechanism which is communicated with the bottom portion of said hopper member and is kept at the same constant temperature as that of said hopper member, and is equipped with a filling nozzle means capable of weighing and discharging the viscous substance to be filled by a predetermined amount at a predetermined cycle, a capsule body loading board which can align and accommodate, in capsule body accommodating holes formed therein, a plurality of hard capsule bodies into which the viscous substance is to be filled, a reciprocating feed mechanism for the capsule body loading board, which transfers said capsule body loading board from a preliminary operating station to a filling station and returns said capsule body loading board back to the preliminary operating station again after completion of the filling, and an intermittent rotary mechanism for the capsule body loading board, which causes said capsule body accommodating holes formed in said capsule body loading board to correspond to the filling cycle of the pumping mechanism at said filling station thereby to sequentially align said accommodating holes with said filling nozzle means.
By the arrangement according to the present invention as described above, an improved apparatus for filling viscous substances into hard gelatin capsules has been advantageously presented, with substantial elimination of disadvantages inherent in the conventional arrangements of this kind.